Metal scaffold connection lock



y 3, 1951 H. R. SCHEIDEMANTLE 2,559,469

METAL SCAFFOLD CONNECTION LOCK Filed Feb. 25, 1949 2 Sheets-Sheet 1 IN V EN TOR.

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y 1951 H. R. SCHEEDEMANTLE METAL SCAFFOLD CONNECTION LOCK 2 Sheets-Sheet 2 Filed Feb. 25, 1949 BY 010 mnw w MQA AL: ATTORNEYS.

Patented July 3, 1951 Howard E. Scheidemantle, Harmony, Pa, as-

signorto Universal Manufacturing Corporation, Zelienople, Pa., a corporation of Pennsylvania Application February 25, 1949., Serial No. 78,404

6 Claims.

This invention relates to scafiolds, and more particularly to those that are assembled in any desired length and heightv from prefabricated endframes connected by removable braces. Such a scaffold is shown in Weisz Patent No. 2,435,171.

It is among the objects of this invention to provide a scaffold in which the removable braces are automatically lockedv in position when connected to the scaffold legs, in which the lock operates by gravity, in which the locking members are permanently connected with the scaffold, and in which the legs of superimposed end frames can be locked in the underlying end frames by the same type of locking members as are used with the braces.

According to this invention, a pair of spaced parallel. end frames are held upright by removable side braces. to form a scaffold. Similar end frames can be placed on top of them. Each end frame preferably has a pair of tubular legs which are rigidly connected together by suitable cross braces. A vertical sleeve is welded to the outside of each leg near its upper end, and another similar sleeve is welded to the leg near its lower end. Each brace has a downwardly extending hollow pin welded to each end. Each pin extends down into a sleeve and is provided in its side wall with a hole. Inside of the pin a cross member is inclined from the bottom of the hole upward across the pin. Resting on the lower part of this cross member is a ball which projects from the hole. Another ball rests on the cross memher behind the first ball to normally hold the latter in projected position. The second ball preferably is smaller than the first. one and engages it substantially midway between its. top and bottom. The projecting ball may project below the lower end of the sleeve. or through a hole in the side of it. The lower ends of the legs of the superimposed end frames also may be provided with similar hollow pins that project down into the upper ends of the underlying legs, or the upper ends of the lower legs may support the pins. These pins are mounted with side holes registering with holes in the surrounding legs. Balls, like in the brace pins, are disposed in the leg pins and project through the registering holes to lock the legs together.

The" preferred embodiment of the invention is illustrated in the accompanying drawings, in which Fig. 1 is an isometric view of my scaffold; Fig. 2 is an enlarged fragmentary vertical section through a pair of connected legs taken on the central vertical plane of an end. frame; Fig. 3 is a vertical section through a brace pin and sleeve showing the pin being removed; Fig. 4 is a. horizontal section taken on the line IVIV of Fig. 2; and Fig. 5- is a vertical section through a modification of this invention.

Referring to Fig. l of the drawings, a pair of spaced parallel prefabricated end frames each has. vertical tubular legs I. rigidly connected at their. upper ends by a horizontal brace 2 upon which wooden planking (not shown) may be placed to form a working platform. Crossed inclined braces 3 connect the horizontal brace to the lower portions of the legs. When the sealfold is assembled, the end frames are held upright by means of crossed side braces 4 that are inclined, between the legs of one end frame and the legs of the other end frame.

In. order to connect the ends of the braces to the legs, pairs of vertical sleeves 6 are welded to each leg near its top and bottom. The hollow pins 1 at the ends of the braces may have downwardly tapered lower ends to aid in inserting them. in the sleeves, by which the braces are held' in position. Directly, or a short distance below the. lower ends of the sleeves each pin is provided with a circular hole 8, as shown in Figs. 2 and 3, the wall of which preferably tapers outwardly. Extending from the bottom of this hole upward across the inside of the pin is a cross member 9 of any desired width. Normally resting. on. the lower part of this member, as shown in Figs. 2 and 4, is a metal ball II that is slightly larger than the hole 8 so that the ball can project a. material distance from the pin without escaping from it. Gravity tends to hold the ball in its projected position below the sleeve. To more positively hold the. ball in projecting or locking position, there is a smaller ball I2 behind it which also rests on the inclined cross member. The smaller ball engages the other ball and also engages, or nearly engages, the wall of the pin opposite to the hole. For best results, the small ball is of such size that it engages the most rearward point on the large ball; that is, a point midway between the topand bottom of the large ball. With this arrangement it will be seen that if it is attempted to push the projecting ball back into the pin, the smaller ball behind it will prevent such movement. However, when desired, the larger ball can be pushed back into the pin by rotating its projecting portion downward so that its point of contact with the small ball will move upward. This action, combined with inward pressure on the large ball, will roll the small ball upward along the wall of the pin and thereby permit the large one to move back under it. The pin then can be raised in the sleeve, as shown in Fig. 3, to remove it therefrom. The projecting ball also has to be pushed back into the pin in the same manner before the pin can be inserted in the sleeve, but the moment the large ball clears the lower end of the sleeve it will roll out of the side of the pin by gravity as far as it is allowed to by the hole 8 from which it projects.

The same type of connection may be used for locking the lower ends of the legs I3 of superimposed end frames to the upper ends of the lower legs I. In such a case, a hollow pin M, of the same general construction as the one just described, is rigidly mounted in the lower end of each upper leg l3, from which it extends downward into the upper end of an underlying leg I,

as shown in Fig. 2. The two legs rest on top of each other, and the pin holds them in axial alignment. Near its lower end the pin is provided with a transverse cross member l5 that is inclined downward to the bottom of a, hole 16 in the side wall of the pin. Resting on this cross member is a large ball I1. To permit the ball to project from the pin into locking position, the

upper end portion of the lower leg is provided in its side wall, beneath brace 2, with a hole l8 that registers with the hole IS in the pin. The large ball extends through both holes so as to lock the two legs together. The ball is prevented by a small ball l9 behind it from accidentally being pushed back into the pin. The legs can be unlocked and separated in the same manner as the brace pins 1 are removed from sleeves 6.

In the modification shown in Fig. 5 a hollow pin 2| is rigidly mounted in the top of leg I and projects up into superimposed leg I3 that rests on leg I. Near its upper end the pin is provided with a transverse cross member 22 that is inclined downward to the bottom of a hole 23 in the side wall of the pin. Resting on this cross member is a large ball 24. To permit the ball to project from the pin into locking position, the lower end portion of the upper leg is provided in its side wall with a hole 26 that registers with the hole 23 in the pin. The large ball extends through both holes to lock the two legs together. The ball is prevented by a small ball 2'! behind it from aocidentally being pushed back into the pin.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider, to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A scaffold connection comprising a vertical tubular member provided in its side wall with a hole, a scaffold member, a vertical hollow pin extending from said scaffold member into said tubular member, the outside diameter of the pin being slightly less than the inside diameter of said tubular member, the side wall of the pin being provided with a hole registering with said first-mentioned hole, a cross member inclined from the bottom of said pin hole upward across the inside of the pin, a ball inside the pin resting on the lower part of said cross member and projecting through said registering holes to lock the pin in said tubular member, and a smaller ball resting on the cross member behind the projecting ball and substantially filling the gap between the projecting ball and the inner surface of the pin at the upper end of said cross member to prevent the projecting ball from being pushed back into the pin by the wall of said firstmentioned hole if said pin and tubular member attempt to separate.

2. A scaflold connection comprising a tubular leg provided in its side wall with a hole near its upper end, a superimposed scaffold leg, a hollow pin extending downward from said superimposed leg into the first-mentioned leg, the outer diameter of the pin being slightly less than the inside diameter of said first-mentioned leg, the side wall of the pin being provided with a hole registering with said leg hole, a cross member inclined from the bottom of said pin hole upward across the inside of the pin, a ball inside the pin resting on the lower part of said cross member and projecting through said registering holes to lock the pin in said tubular leg, and a smaller ball resting on the cross member behind the projecting ball and substantially filling the gap between the projecting ball and the inner surface of the pin at the upper end of said cross member to prevent the projecting ball from being pushed back into the pin by the wall of said leg hole if the pin attempts to rise in said first-mentioned leg, the size of the small ball being such that it engages the projecting ball substantially midway between the top and bottom of the latter.

3. A. scaffold connection comprising a tubular leg provided in its side wall with a hole near its lower end, an underlying scaffold leg, a hollow pin extending upward from said underlying leg into the first-mentioned leg and having an outer diameter of slightly less than the inside diameter of the first-mentioned leg, the side wall of the pin being provided with a hole registering with said leg hole, a cross member inclined from the bottom of said pin hole upward across the inside of the pin, a ball inside the pin resting on the lower part of said cross member and projecting through said registering holes to lock the pin in said tubular leg, and a smaller ball resting on the cross member behind the projecting ball and substantially filling the gap between the projecting ball and the inner surface of the pin at the upper end of the cross member to prevent the projecting ball from being pushed back into the pin by the wall of said leg hole if said pin and tubular leg attempt to separate, the size of the small ball being such that it engages the projecting ball substantially midway between the top and bottom of the latter.

4. A scaffold connection comprising a vertical hollow pin extending from a scaffold member into a vertical tubular member having a side wall provided with a surface facing downwardly, the outer diameter of the pin being slightly less than the inside diameter of said tubular member, the side wall of the pin being provided with a hole, a cross member inclined from the bottom of said hole upward across the inside of the pin, a ball inside the pin resting on the lower part of said cross member and projecting from said hole and beneath said downwardly facing surface to lock the pin in said tubular member, and a smaller ball resting on the cross member behind the projecting ball and substantially filling the gap between the latter and the inner surface of the pin at the upper end of the cross member to normally hold the projecting ball in projected position, the size of the smaller ball being such that it engages the projecting ball substantially midway between the top and bottom of the latter ball.

5. A scalTold connection comprising a vertical hollow pin extending from a scaffold member into a vertical tubular member having a side wall provided with a surface facing downwardly, the outer diameter of the pin being slightly less than the inside diameter of said tubular member, the side wall of the pin being provided with a hole, a cross member inclined from the bottom of said hole upward across the inside of the pin, a ball inside the pin resting on the lower part of said cross member and projecting from said hole and beneath said downwardly facing surface, and a smaller ball resting on the cross member behind the projecting ball and substantially engaging the inner surface of the pin at the upper end of the cross member to normally hold the rojecting ball in projected position, and the size of the smaller ball being such that it engages the projecting ball substantially midway beween the top and bottom of the latter, whereby the projectingsurface of the projecting ball must be moved downward manually to cause that ball to lift the smaller ball in order to make it possible to push the projecting ball back into the pin.

6. A scaffold connection comprising a hollow pin extending from a scaffold member downward through a vertical sleeve and projecting from the lower end of the sleeve, the outer diameter of the pin being slightly less than the inside diameter of the sleeve and the projecting lower portion of the pin being provided in its side wall with a hole, a cross member inclined from the bottom of said hole upward across the inside of the pin, a ball inside the pin resting on the lower part of said cross member and projecting from said hole and beneath said lower end of the sleeve, and a smaller ball resting on the cross member behind and in engagement with the projecting ball and substantially in engagement with the side wall of the pin at the upper end of the cross member, the size of the smaller ball being such that it engages the projecting ball substantially midway between the top and bottom of the latter.

HOWARD R. SCHEIDEMANTLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

